1. Field of the Invention
The present invention relates to an inter-entity coupling method, an inter-entity coupling apparatus, and an inter-entity coupling system for service protection in a broadcast environment.
2. Description of the Related Art
In general, a broadcast service refers to a service scheme in which if a server controlling the broadcast service transmits an encrypted service, then a plurality of terminals can receive the encrypted service.
At present, broadcast services have been changing into charged services (e.g., pay-per-view, subscription, etc. services). In this regard, a Digital Rights Management (DRM) technology providing convenience and flexibility and using a user's Rights Object (RO) has been introduced to provide copyright protection and for preventing unauthorized reproduction and distribution of content.
Service and/or content provided from a service provider is/are protected as shown in FIG. 1 which is a block diagram illustrating the configuration of a conventional DRM system. The DRM technology is a typical security technique for protecting content and stipulates the rights of use for encrypted content. Entities playing roles in DRM communication include a terminal system 3 which reproduces content using an RO, and a Rights Issuer (RI) which creates and issues the RO defining the rights of use for the content and so forth. As shown in FIG. 1, the RI belongs to a service provider 5.
The terminal 3 establishes a safe channel through an authentication procedure with the RI, and acquires the RO over the established channel. At this time, since the RO is decrypted using the DRM technology, it is possible to prevent content from being used without authorization. That is, a user cannot enjoy multimedia information included in the encrypted content before the encrypted content is decrypted and executed using the DRM technology and the RO.
Conventional service and/or content protection methods perform an authentication procedure between a service provider and only one terminal. A typical related standard in a mobile communication environment includes the Open Mobile Alliance (OMA) DRM v2.0. However, a standard related to service protection for a plurality of terminals using the broadcast service in the mobile communication environment has not yet been proposed.
Furthermore, although several content protection methods in the broadcast environment exist, for example, an Multimedia Broadcast/Multicast service (MBMS) and a BroadCast MultiCast Service (BCMCS) exist using the Third Generation Partnership Project (3GPP), 3GPP2, etc., the methods are dependent on networks such as the 3GPP and so forth.
As stated above, conventionally, only dependent service and/or content protection methods, such as an MBMS method dependent on the existing 3GPP network, exist as opposed to methods which are independent of specific networks. Thus, there is a need for a structure of entities participating in a broadcast network and a method for coupling the respective entities with each other, which can be applied to various networks.